


Tackle Her Heart

by AngleJoyce



Category: Deltarune (Video Game)
Genre: Alcoholism, Alphyne, Alphynecentric, Alphys/Undyne-centric (DeltaRune), Betrayal, Deltarune - Freeform, Depression, Emotional Manipulation, F/F, Hiding Issues, Ideas Comments And Likes Are More Than Welcome!, Implied/Referenced Self-Harm, Mistakes, More tags to be added, No Outline, Please Don't Hate Me, Rating May Change, Slow Burn, Strangers to Friends to Lovers, The Angst Train With A Shitload Of Angst Is On The Way!, Trust Issues, Word Count Differences Each Chapter
Language: English
Status: In-Progress
Published: 2019-03-06
Updated: 2019-03-19
Packaged: 2019-11-12 07:26:01
Rating: General Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 4
Words: 4,068
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18006440
Author URL: https://archiveofourown.org/users/AngleJoyce/pseuds/AngleJoyce
Summary: Alphys promised herself one thing: "Don't fall in love again."That promise gets harder and harder to keep.





	1. Chapter 1

**Notes for the Chapter:**

> I got so upset by Alphys and Undyne not knowing each other (yet???) in DeltaRune chapter 1, that I _had_ to write a fic of them meeting - and eventually falling in love, too. 
> 
> This story has no outline or plot, so feel free to give me some ideas! Anything is fine! ^^

"Hey, _you!_ " Was the first thing Alphys was greeted with when she set a step outside of the school. She didn't even have a chance to lock the school's doors (usually Toriel did that, since she stayed longer than Alphys, but the headmistress had went home earlier, today). Before she could even blink or look up, she was tackled to the ground. Hard.

"Hmpf--ouch!" Alphys yelped when she hit the ground, before opening her eyes, her breaths quickening up in her panic.

Lying on top of her and keeping her in place was...

"O-officer Undyne?" Alphys stammered out.

The blue fish lady grinned widely, showing her sharp teeth. "That's me. And you're Alphys, right?" When Alphys just looked at her in shocked surprise and stayed silent, Undyne repeated, "Right?!"

"U-uhm! Y-yes! What's the problem?" she asked, swallowing hard. After she'd gone to therapy for it, Alphys didn't stutter as much as usual. But when she was put under pressure, or when she was scared or panicking, she tended to fall back in her old habit.

"Some punk told me you've been doing illegal stuff. So spill. I'm not letting you go anywhere before you confess."

"Il..illegal stuff..?" Alphys's eyes widened underneath her glasses. "No, I would never! Who told you that?"

"Asgore's kid. Don't change the subject now!" Undyne growled. It should be noted that Undyne was still lying atop of Alphys during all of this, not moving an inch.

"Officer, I-I think they pranked you..? I- I don't have anything to hide!"

"Then you don't mind if I come with you to investigate your house," Undyne countered.

Alphys shook her head, smiling shakily. "Of course not..! B-but, uhm, can you get off me, now..?"

"Right." The officer's cheeks turned a bit red - was that a blush? - and she moved off Alphys, getting to her feet and holding out her hand to Alphys. But Alphys didn't accept the offer and got to her feet by herself, dusting off her skirt. "So, your house?" Undyne's hand dropped back to her side. 

Alphys nodded slowly, still wary, and began to walk with the other female.

* * *

Undyne blinked when they stepped in Alphys's little apartment. It was a small mess. There were a few ramen wraps lying here and there, as well as a few papers, scattered over the living room floor nearby the couch.

Undyne stepped forward, trying to avoid all the things on the floor and stepping over them. On her left she saw two doors, next to each other. And in the back of the living room, on the left as well, was a small inlet to the kitchen. 

"It's quite, uh, messy, here," Undyne started, looking around and scratching her cheek. Alphys blushed, glancing away. 

"Yeah, I know," she answered. She watched as Undyne searched around the living room, before she walked into the kitchen and looked there in the cabinets, her eyes narrowed.

"Would you like something to drink?" Alphys questioned softly as Undyne got out of the kitchen. 

"Nah I'm good." She walked over to the first door she'd seen and placed her hand on the doorknob. "I'm gonna check this room now." 

Alphys nodded, going to the kitchen to get herself something to drink - soda - while Undyne checked her bedroom. She bit her bottom lip, a wave of nervousness washing over her.

She never had anyone in her apartment before, save sometimes Asgore, to catch up and talk, or to lend him comic books again - and in return she always got flowers. In the beginning she tried to tell him he didn't need to give her anything in return, but when she saw how happy it made him when she accepted the flowers, she never spoke up about it again.

A soft sigh escaped her lips and she sat down on her couch, putting her glass on the small coffee table and glancing towards her open bedroom door, hearing Undyne rummaging through her stuff.

Truly, she didn't have anything to hide. But it still felt embarassing  to have Undyne look through all of her possessions - she knew a lot of her stuff was childish, because she simply was an immature adult, and always had been. It bothered her, but it never seemed to bother anyone around her (aka Asgore, Toriel, and her students), save Toriel, who sometimes really didn't like Alphys's stubbornness. But then, Toriel and Asgore were the only monsters Alphys was kind of herself with. She almost always wore a mask in front of everyone. Toriel was an exception. Kinda. And Asgore too, she thought with a blush. She knew she didn't need to, with Asgore. Yet sometimes, she did it without even noticing it herself, until too late. 

She knew, when she was completely herself with someone, that they would leave her. It had happened before, a few times, and she was still hurt by it. A lot. And she didn't want to risk it again.

She didn't know how much time she sat there thinking about everything, until Undyne stood next to her and said, "Alright, I'm done here."

Alphys blinked, looking at her. "S-so? Found anything?"

The officer sighed, her earfins drooping. "No. Sorry for bothering you, miss."

"It's okay! R-really!" Alphys smiled up at her. "But why did you believe them, anyways?"

Undyne scratched the back of her head, looking..disappointed?

"Something never happens in this town and it's really boring," she started, "so when I think or get to hear anything, literally anything at all, I immediately get excited because I hope there's finally some crime to fight, y'know?" 

Alphys nodded understandably. "Yeah, that..does make sense."

"So when I got to hear from Kris that there was an Alphys who was doing illegal stuff, I got so hyped!!" Her hands clenched into fists in front of her, a grin coming to her face in her excitement. "I thought it had something to do with the other drug dealer who _I know_ lives somewhere in this town, that maybe there was a connection or something!" Her grin faltered and she dropped her hands at her sides. "Alas, nothing."

"Oh," Alphys murmured. "I'm sorry, I didn't know..."

Undyne shrugged. "Don't worry, it's okay. Just boring. But that's not the worst thing that's happened to me." A grin came back to the fish's face. "I shall take my leave now. Again, sorry for bothering you."

"It's okay," Alphys admitted, smiling. 

Undyne nodded, zipping up her jacket. Alphys walked her to the door and Undyne did a small salute, grinning, before walking down the stairs. Alphys called out a soft "bye", then closed the door behind her and sighed deeply, putting a hand to her chest and feeling her heart racing.

Well... That was certainly something.

**Notes for the Chapter:**

> Feedback, criticism, ideas (including smut and angst ideas - literally anything), everything is greatly appreciated! I hope you liked the chapter!


	2. Chapter 2

"So... I met someone new yesterday," Undyne said softly, taking a sip of her tea after finishing her sentence.

She and Asgore were sitting in Asgore's little flower shop, in his "bedroom" on the floor and drinking Asgore's homemade tea, like they always did every Saturday. 

"Oh?" Asgore said, looking at her. "Who is it?"

"Her name is Alphys, if I remember it correctly. She lives in the flat near the alley."

Asgore's eyebrows went up. "And how did you two meet?"

Undyne's cheeks suddenly turned red. "Uh. K--some kid hinted that she was doing illegal stuff, so I searched her in the town's register and then followed her for two days." Undyne's fingertips tapped against the mug she was holding. "And since she always goes to the alley behind her flat every night, she seemed very suspicious..." She sighed. "I confronted her at the school yesterday, while she was locking up, and then we went to her apartment and I rummaged through her house and stuff. And I found nothing at all." She frowned.

"Oh dear!" Asgore smiled. "Alphys wouldn't do something illegal or criminal!" He laughed softly. 

"Then why--?"

"She always puts a bowl with milk outside in the alley for her cat, every night," Asgore explained, still chuckling softly. 

Undyne felt even more stupid now. "Oh. Well. Uh. Do you know her?"

"I do, indeed," he said, his smile softening. "Me and her dated in the past, even! Luckily we broke apart peacefully, and are now really good friends."

Undyne choked on her tea. "You two _dated?_ " 

"Yes," Asgore said, grinning softly, unable to help it. Undyne's reaction was priceless. 

"Well- how was it?" Undyne asked hesitantly. She really wanted to know more about this Alphys...

"It was very nice," he admitted, his own cheeks heating up a little. "But we had to break up because the teachers didn't approve. We tried to date in secret for a while after that, but they found out again. After we broke up again, we lost contact because I moved away - money problems. Then I met Tori, a few years later, and moved back here. When me and Alphys got in contact again, it was like we never had lost contact." He smiled. "She is a great person."

"What does she like?" Undyne wondered. 

"She likes videogames, and anime -  they are cartoon movies and series. It's better than I'd expected! Oh, and also writing and reading!" He grinned, then blinked, realizing something. "Dear, why are you asking me all about her?"

Undyne shrugged. "I don't know. I'm just curious." She hesitated, then spoke up. "It's weird. She's lived here longer than I've been chief of the police, yet I've never seen her until yesterday."

"Ah, well, she tends to stay in her apartment as much as she can," he admitted. "She doesn't find herself a very social person."

"But, in those _seven years_ I should have seen her _at least once_ , right? Isn't that strange?"

Asgore shrugged. "Honestly, I do not know an answer to that. It's a bit unfortunate, yes, but sometimes things like that happen. Maybe you weren't meant to meet yet until now."

Undyne sighed, her shoulders drooping. She took another sip of her tea and decided to change the subject. But she still didn't trust Alphys. 

* * *

"Hello dear!" Toriel chirped, welcoming Alphys with a hug. Alphys blushed slightly, and returned the hug nervously. "H-hi, Toriel."

"I'm so glad you could come over and have dinner with us! It's been a while, hasn't it?" She pulled back, smiling softly as she stepped aside so Alphys could walk in. The house already smelled like Toriel's delicious snail casserole.

"Y-yes! It's been..a few weeks, now, right?" she added to Toriel. The goat nodded, closing the door behind the two of them, before walking to the kitchen with Alphys.

"Hi, Kris," Alphys said, smiling faintly. Kris looked up from the game they were playing on their Nintendo, waving once with a smile, before looking back down and continuing their game.

"Please sit down, dear. Dinner will be ready soon," Toriel said, her body leaning against the kitchen counter as she waited for the oven to ping.

"R-right," Alphys stammered, before taking seat at a chair at the table. She fumbled with a bracelet around her wrist, looking at her hands in her lap as she did so. She always felt pretty nervous at first when she was with Toriel. She still didn't know why, since they had been friends for a year, now.

"So, how have you been, Alphys?" Toriel wondered. The oven pinged, and she smiled, putting on her mittens, turning off the oven and opening the door, before getting out the casserole. 

"I- uhm, I've been doing good!" Alphys smiled nervously. "And you?"

"Me, too," she said softly. She put the casserole on the middle of the table and sat down on a chair next to Alphys, her ruby eyes locking with Alphys's for a moment as she smiled (Alphys blushed and glanced away).

"Now, shall we eat?" Toriel announced. Alphys nodded with a smile, while Kris put away their gaming device and nodded as well, smiling. 

* * *

"So..why did you tell officer Undyne that I was doing illegal stuff?" Alphys wondered. She and Kris were sitting in the living room after she had helped Toriel with the dishes. Now Toriel was making the three of them tea. Alphys had waited to have a moment with Kris alone, so that Kris wouldn't get in trouble, would it all be a misunderstanding.

"I didn't," they said calmly. "I asked her if she knew you, and when she said no, she immediately added: ' _Why are you mentioning her? Is she doing bad stuff or something? Oh hell yeah! Thank you for telling me, I will definitely get to her when I see this Alphys!_ ' or something. She didn't even let me finish my sentence. And when I wanted to tell her you were just my teacher she was already doing something else. I never got the chance to correct her."

Alphys chuckled. "Well, she did confront me and searched my house."

Kris let out a soft snort, unable to help it. "Wow, she actually did huh?" When Alphys nodded with a chuckled, Kris smiled faintly. "Isn't really surprising though. Her job's boring, so she grasps every opportunity she has for any kind of action."

Alphys nodded. "Do you think she still suspects me of something?" she wondered.

"I'm not sure. Undyne is very unpredictable."

Alphys nodded in agreement.

Undyne was, indeed.

**Notes for the Chapter:**

> Feedback, criticism, ideas (including smut and angst ideas - literally anything), everything is greatly appreciated! I hope you liked the chapter!


	3. Chapter 3

"Heya Teach!" Undyne greeted, suddenly standing behind Alphys. Alphys almost dropped her bag with groceries in surprise, turning to Undyne quickly.

"Uh, hi!" the teacher squeaked out, swallowing hard. "What- uhm- do you need anything?"

Undyne grinned, her hands resting on her hips. "Maybe. What are you up to?"

"Oh." Alphys's cheeks reddened in nervousness. What did Undyne want from her? "I-I'm on my way home from the store. Why?"

"No reason." Her grin softened to a smile. "Hey, I just wanted to apologize for last week. I shouldn't just have accused you of things like that." She scratched her cheek. "So, uhm, would you maybe like to go to a diner or the local café something, so that I can make it up to you?"

Alphys looked at Undyne in silence, her eyes widening a bit. Then she caught up and realized she needed to respond. "Oh- uhm. Uh. B-but I already forgave you. You don't have to." A nervous smile made her way onto Alphys's face.

"I know, but I wanna! 'else I'll keep feeling guilty!" She chuckled. "So? What about tomorrow after your lessons, we'll catch a drink at the café?"

Alphys blushed, looking down at her feet, feeling shy all of a sudden. "Uh. Okay. Yeah!" She smiled up at Undyne. "Sounds great!"

"Alright! See ya tomorrow Alphys!" She grinned and turned around.

"Yeah, see you tomorrow," Alphys called after her, her hands fumbling with the hem of her shirt.

* * *

Of course, the next day, Alphys brought clothes with her to change in the teachers locker room, for her hangout with Undyne. She couldn't show up in a café wearing her work clothes. So when she stepped out of the school and locked it up (yes, again), she wore a white dress (with a hole for her tail, even) with a pink long-sleeved jacket. She almost felt cute in this outfit.

Alphys looked around, fumbling with the bracelet around her wrist as she waited nervously. Somewhere in the back of her mind she wondered why she'd even put effort in her outfit for a hangout with someone she'd never see after this again - with Undyne, who only wanted this one hangout with her, just so that she could feel better about herself and her actions and what she'd done to Alphys.

She sighed softly, sitting down on a bench next to the school, resting her hands in her lap. She wondered if Undyne would even show up at all.

It took 10 more minutes, but eventually, Undyne showed up - on a motorbike. A red and black MV Augusta F4 LH 44, to be exact. And while Alphys wasn't that much into motors and vehicles, this one looked _hot_. Her eyes went over Undyne's outfit - red shirt, blue jeans, red boots and a black jacket - and she let out a soft sigh; apparently, Undyne also put effort into her own outfit, so she didn't feel as if she'd done too much effort.

"Heya Teach!" Undyne greeted again, taking off her helmet - also red and black - and shaking loose her hair. "Sorry for the delay, some guy called because of a fight with his neighbor." She rolled her eyes, then grinned. "Anyways, hop on! I got a spare helmet in the back!"

Alphys got up with a slight blush, stammering out something and moving to grab the spare helmet. She tried to put it on, but her headspikes got in the way, and she blushed even more, though this time out of embarrassment. 

"Oh," Undyne simply said. Then she grinned. "Ah, don't worry about it. It's not that required, plus I'm always a safe driver!"

"R-right," Alphys muttered, before climbing on the motor behind Undyne - with her help, of course.

"Hold on tight," Undyne said, starting up the engine again. Hesitantly, Alphys wrapped her arms around Undyne's waist, and if Undyne hadn't worn her helmet, Alphys could've seen het grin.

With a roar coming from the motorbike, they took off.

* * *

Alphys had expected things to turn out miserable. Instead, she found herself actually having fun with Undyne. They ordered foods and drinks and talked and laughed a lot, Undyne also sharing some shenanigans from her work. 

By the time Undyne dropped Alphys off at her apartment, it was already dark outside.

"Uhm," Alphys stammered as she stood in front of the hall door. "Th-thank you, for today," she murmured gratefully. "I really had a lot of fun."

Undyne flashed her a grin. "Of course." She then took out her phone, and said, "Wanna exchange numbers so we can do this again some time?"

A blush made its way onto Alphys's cheeks, and she nodded shyly, getting out her own phone as well. They exchanged numbers, and Undyne put her helmet back on, still grinning. "Alright, I'll text ya later Alphys." She started the engine and Alphys nodded in agreement.

Undyne chuckled, before she drove away towards her own place.

Alphys sighed shakily, a huge smile on her face, and she opened the hallway door before making her way to her apartment.

When she fell asleep that night, she didn't have nightmares for once.

**Notes for the Chapter:**

> Feedback, criticism, ideas (including smut and angst ideas - literally anything), everything is greatly appreciated! I hope you liked the chapter!


	4. Chapter 4

**Notes for the Chapter:**

> Okay uhm things are is kinda starting now
> 
> I hope you guys still like the story so far!

It was so wrong.

Wrong.

Dangerous.

 _Illegal_. 

But the necessity outweighed all of that.

It couldn't happen.

It needed to be done.

Even if every fibre in the body screamed to not do it.

* * *

It had been a few weeks now since Undyne and Alphys's first hangout. The two of them talked over text, but both were too busy with work to hang out again. Though, Alphys was convinced Undyne didn't want to see her any more. 

So when Alphys received a text from Undyne saying, "Hey Teach, wanna hang out again?" Alphys felt kind of surprised.

Over text, they agreed on a time and place, and when they stopped texting Alphys had that smile on her face again.

It soon faded away when Toriel walked into the classroom after lessons, smiling, though wider than usual - which surprised Alphys.

"Alphys!" the headmistress chirped.

Alphys suddenly found herself pulled into a hug and she stammered something incoherent, hugging back with surprise. "Toriel, are you okay?"

"Yes! I'm wonderful!" She grinned, her fangs showing.

"Is... Is this about the budget?" Alphys suddenly wondered, fear filling her.

"I don't know how you did it, but it worked!" Toriel said. Much to Alphys's suprise.

"It-it did?" Alphys wondered.

Toriel nodded. "Yes! I know you said you'd look into the bills and payments, and try to find a way to save more money, and it worked!!" That big smile was still on her face. "I haven't been able to take a look before this morning, and I saw you've saved a decent amount of money this month! Alphys, thank you so much!" She leaned down and hugged the teacher once again, who blushed hard, but hugged back nonetheless. 

Toriel wondered how Alphys had saved almost half as much money as their monthly income, but when she thought about it, it was very possible. Her school, which had been threatening to go bankrupt, was now saved. And all thanks to Alphys.

"Y-yeah... No problem!" she stammered, smiling widely. "Now you can finally buy the better equipment for the school!"

"I know!" Toriel let go of Alphys, before clasping her hands together as an idea struck her mind. "I'm going to do that right away, now, dear! Thank you! And keep up the good work!" 

When Alphys nodded and smiled awkwardly, Toriel left the classroom.

Alphys squealed softly, unable to help it. She... She had saved Toriel's school.

She'd never felt this proud of something she did. Ever. 

...probably because she was rarely ever satisfied with herself and her work.

She shrugged that thought off for now and packed her stuff, before leaving the classroom, then the building, and then went home, ready to spend her night bingewatching shows on her bed with her laptop.

* * *

That Saturday, Alphys and Undyne met up at Alphys's place, and then went to a multicultural café fifteen minutes away from the town, which Alphys absolutely loved- they had bubble tea! That stuff was only available in Japanese cafes and conventions! 

Undyne had ordered some kind of Japanese tea, and they also ordered a plate of delicacy which they hadn't heard of, before, and ended up loving (it was called Kapishan, they were a kind of sweet buns in different flavours). And so Undyne got to love Japanese delicacy and drinks as well - she hadn't tried anything Japanese before.

After that they went to see a movie together, one with a really difficult name but was amazing. It had action, romance, comedy and just a tiny bit of drama in it. A perfect combination, really.

By the time the movie was finished, it was almost 6 PM, so they decided to grab dinner together as well.

It was one of the best days Alphys had ever had, really. It was all really simple, but she never had a real friend to do these kinds of things with. Toriel was simply too busy, and she was too shy to ask Asgore, as well as that she was afraid of rejection.

One time she had asked him to the movies, and he had said he was too busy for that, along with a lot of apologies. But in truth, Asgore couldn't afford anything. He had barely enough money for monthly groceries. Though Alphys didn't know that, and had just assumed that Asgore didn't like her company - but it was quite the opposite, really. He loved Alphys's company.

Alphys let out a soft sigh, unable to help it while thinking back of that moment.

Undyne looked up at her, blinking. After swallowing her bite of hamburger, she spoke up. "What's the matter?" 

"E-er, nothing important. Just..thinking of something." Alphys smiled sheepishly.

"Alright, then." Undyne took another bite of her hamburger, as Alphys took a sip of her milkshake. 

"So," Alphys started. "Anything new happened, recently?" 

Undyne nodded, finishing her burger before speaking up. "I'm on a new case right now. Someone did some _real_ nasty illegal shit, and now I'm in contact with human police, because they blame one of our citizans. They're acting all like, 'Oh our humam citizens would never do something like that ever'," Undyne said in an annoyed tone. "Fucking assholes, always blaming us." She grumbled something under her breath, then took a sip of her coffee. "Now I have to find out who did it." 

Alphys was silent for a moment, thinking. "What exactly happened?"

Undyne hesitated. 

She remembered her plan and felt her heart clench with guilt. But she needed to do it... She knew she was right about _something.._.

"Nothing. Don't worry about it." Undyne said, taking another sip from her coffee.

Alphys nodded, folding her hands in her lap and fiddling her thumbs. "Alright then."

Undyne smiled softly, her blue eyes locking with Alphys's yellow ones, and she saw the lizard blush, and felt herself grin softly at that.

Her plan was going to work, and it was going to be easy, too.

Even if it was so, so wrong.

**Notes for the Chapter:**

> Feedback, criticism, ideas (including smut and angst ideas - literally anything), everything is greatly appreciated! I hope you liked the chapter!
> 
> I cleaned out my Tumblr a bit, go and check it out if you want to! 
> 
> https://anglejoyce.tumblr.com


End file.
